Over 30 percent of all terrorist attacks from 1970 to 2008 occurred in just five metropolitan U.S. counties, according to a report published today by researchers in the National Consortium for the Study of Terrorism and Responses to Terrorism (START), a Department of Homeland Security Science and Technology Center of Excellence based at the University of Maryland and the University of Massachusetts-Boston.  So what areas should you avoid, if you play the odds?

Way out in front is Manhattan, with 343 attacks.  Los Angeles is next with 156 followed by Miami (103 attacks), San Francisco (99 attacks) and Washington, D.C. (79 attacks).  That doesn't mean the rest of the country is immune.  The study found that 65 of America's 3,143 counties were "hot spots" of terrorism, a 'hot spot' being defined as a greater than average (the average was six) incidence of terrorist-type attacks during the 38-year period studied. 

Just outside the top five is Maricopa County, Ariz., which includes Phoenix, which has emerged as a hot spot in recent years due to fringe left-wing terrorist groups like the environmentalists in Coalition to Save the Preserves.

Gary LaFree, director of START, professor of criminology at the University of Maryland and lead author of the new report, said certain counties were more prone to a particular type of terrorist attack. They found that most attacks were motivated by a single ideological type.  The Bronx in New York only experienced extreme left-wing terrorism, for example, while Lubbock County in Texas only experienced extreme right-wing terrorism.

They also found time trends in terrorist attacks.  Some times were more fashionable in certain periods. "The 1970s were dominated by extreme left-wing terrorist attacks," said co-author Bianca Bersani, assistant professor of sociology at the University of Massachusetts-Boston. "Far left-wing terrorism in the U.S. is almost entirely limited to the 1970s with few events in the 1980s and virtually no events after that."

True enough.  No one vilifies Patty Hearst any more and Bill Ayers of the Weather Underground (and friend of President Obama) got a loving nod from The New York Times the day the World Trade Center was attacked in 2001 about his desire to bomb the Pentagon. Ethno-national/separatist terrorism was concentrated in the 1970s and 1980s, religiously motivated attacks occurred predominantly in the 1980s and extreme right-wing terrorism was concentrated in the 1990s.

To define the ideological motivations, they used START's Profiles of Perpetrators of Terrorism - United States (Miller, Smarick and Simone, 2011), which briefly describes ideological motivations as:

Extreme Left-Wing: groups that want to bring about change through violent revolution rather than through established political processes. This category also includes secular left-wing groups that rely heavily on terrorism to overthrow the capitalist system and either establish "a dictatorship of the proletariat" (Marxist, Leninists, Maoists, Trotskyites, anyone else at a San Francisco peace rally) or, much more rarely, a decentralized, non-hierarchical political system (anarchists).

It's a shame they didn't include those people holding disease parties and refusing to vaccinate their kids.

Extreme Right-Wing: believe that one's personal and/or national "way of life" is under attack and is either already lost or that the threat is imminent (for some the threat is from a specific ethnic, racial, or religious group), and believe in the need to be prepared for an attack either by participating in paramilitary preparations and training or survivalism. Groups may also be fiercely nationalistic (as opposed to universal and international in orientation), anti-global, suspicious of centralized federal authority, reverent of individual liberty, and believe in conspiracy theories that involve grave threat to national sovereignty and/or personal liberty.

Religious: groups that seek to smite the purported enemies of God and other evildoers, impose strict religious tenets or laws on society (fundamentalists), forcibly insert religion into the political sphere (e.g., those who seek to politicize religion, such as Christian Reconstructionists and Islamists), and/or bring about Armageddon (apocalyptic millenarian cults; 2010: 17). For example, Jewish Direct Action, Mormon extremist, Jamaat-al-Fuqra, and Covenant, Sword and the Arm of the Lord (CSA) are included in this category.

Ethno-Nationalist/Separatist: regionally concentrated groups with a history of organized political autonomy with their own state, traditional ruler, or regional government, who are committed to gaining or regaining political independence through any means and who have supported political movements for autonomy at some time since 1945.

Single Issue: groups or individuals that obsessively focus on very specific or narrowly-defined causes (e.g., anti-abortion, anti-Catholic, anti-nuclear, anti-Castro). This category includes groups from all sides of the political spectrum.